A process for producing bodies by spraying an atomized molten metal or alloy on a target surface and a device required for carrying out this process are known from DE-PS 36 17 833, wherein a relative movement is produced between the target surface and the atomized spray in the circumferential direction of the body to be produced. In order to prevent oxidation of the atomized metal/alloy, according to the above-mentioned German patent, the work process is performed in a protective gas atmosphere in a tank. In the region of the through-opening of the tank, the body trailing from the end of the workpiece holding device passes a gas seal which is intended to prevent the penetration of oxygen into the interior of the housing. The seal, which is only suggested in the drawing and is not described in more detail in the patent, is not suitable for solving the problems occurring in this location. Air is constantly being sucked in under the rough conditions of the metallurgic operation so that the atomized spray is oxidized. Moreover, rigidified particles of metal escape from the housing through the opening, resulting in high maintenance costs and infraction of current environmental regulations and standards.
Further, a pipe coating device having a housing which comprises double-walled through-opening air-lock chambers connected to a device for producing vacuum pressure is known from JP 02-198 657 (Patent Abstracts of Japan C-771, Vol. 14, No. 480, 10/19/1990).
Finally, it is known from DE 31 66 368 A1 to provide atomizing devices with through-opening diaphragms which are rotatably supported.